Many engines and compressors use a camshaft, a pushrod and a rocker arm mechanism to functionally operate valves and/or unit fuel injectors. Typically, such components operate as a tuned combination and the engine or compressor operates smoothly. However, under certain conditions such as engine overspeed, injector seizure or valve spring breakage, the upper end of the pushrod can lose contact with the rocker arm and fall to one side. When this happens, the rotating camshaft moves the pushrod into contact with nearby components of the engine with sufficient force to seriously damage the components of the engine. Another mode of damage occurs when the pushrod falls into rotating components such as the camshaft. If misalignment of the pushrod and the cam follower occurs, the rocker arm will no longer move the valves or the injector, thus malfunction of the engine will occur.
An example of a device to prevent this from occurring is disclosed in U.S. Pat. No. 3,963,280 issued to Phillip E. Irving on June 15, 1976. In such system, the pushrod guide or locator is attached to a stud on a cylinder head. The guide is made up of two planar portions having an angular and planar relationship to one another. This relationship is required to appropriately position the mounting to the engine with respect to the reciprocating movement of the pushrod. The guide has a slot therein in which a bushing having a peripheral groove is positioned. The bushing has a bore therein through which the pushrod passes. Angular and reciprocal movement of the pushrod is compensated for by the bushing's peripheral groove moving in the slot. A pushrod guide of this design requires a stamped or formed plate and a machined bushing to functionally guide and locate the pushrod. The movement of the bushing with respect to the plate will cause wear and eventual malfunctioning of the engine or compressor. Furthermore, the assembly of the plate to the head requires the plate to be attached and properly aligned with respect to the pushrod location. The assembly of the bushing, pushrod and plate during the assembly of the engine increases the complexity of the alignment and assembly technique thus adding time and cost with the end result being reduced profitability.
The present invention is directed to overcome one or more of the problems set forth above.